Detection of nighttime sea fog/stratus over the Huanghai Sea using MTSAT-1R IR data

A dual channel difference (DCD) method is applied to detect nighttime sea fog/stratus over the Huanghai Sea using the infrared (IR) data of shortwave (3.5–4.0 μm) and longwave (10.3–11.3 μm) channels from the Multi-functional Transport Satellite (MTSAT)-1R, i.e., shortwave minus longwave brightness temperature difference (SLTD). Twenty-four sea fog events over the Huanghai Sea during March to July of 2006 and 2007 are chosen to determine a suitable value of SLTD for nighttime sea fog/stratus detection, and ...     

Growth of marine bacteria and ammonium regeneration from substrates in different C: N ratios

Natural assemblages of marine bacteria were chosen in a batch culture experiments. The impact of varying nitrogen substrate concentrations and the substrate C:N ratios (C:N_S) on the bacterial C:N ratio (C:N_B), the bacterial growth efficiency (BGE) and ammonium regeneration was mainly examined. The C:N_S ratios varied from 5:1 (carbon limitation) to 40:1 (nitrogen limitation) with varying combinations of glucose and NO₃^-. The C:N_B ratio had positive relationship with the C:N_S ratio (r=0.93, n=8), whose value was 3.77 when the C:N_S ratio was 5:1 but increased to 6.47 when the C:NS ratio was 40:1. These results indicate that the C:N_B ratio is a potential diagnostic tool for determining the bacterial growth in natural waters controlled by either, carbon or nitrogen. BGE decreased with the declining nitrate concentration and negatively related to C:N_s (r=-0.51, n=8). The average value of BGE was 0.20. This value was a little lower than other reports, which could be induced by the nitrogen source used in our experiments. Finally, regeneration time of ammonium delayed with the increasing C:N_S ratio, which indicates that there were different metabolism mechanisms when bacterial growth was limited by carbon source and nitrogen source.     

镉和汞两种重金属离子对四角蛤蜊的急性毒性

采用毒理学实验方法,比较研究了Cd~(2+)和Hg~(2+)对四角蛤蜊(Mactra veneriformis Reeve)急性毒性效应的差异,以期为进一步评价重金属离子对四角蛤蜊的毒性效应和作用机理等提供理论依据.死亡概率单位和实验液浓度对数的线性回归分析表明,Cd~(2+)对四角蛤蜊在24、48和96 h的半致死浓度(LC_(50))分别为15.961、5.149和2.383 mg/L,Hg~(2+)的LC_(50)分别为3.714、0.607和0.207 mg/L;Cd~(2+) 和Hg~(2+) 对四角蛤蜊的安全质量浓度分别为0.023 8 mg/L和0.002 1 mg/L,分别是我国渔业水质标准(GB11607-89)限定量的4.76倍和4.02倍.     

栉孔扇贝(♀)×虾夷扇贝(♂)子一代杂种优势的SRAP分析

采用新型的分子标记技术(Sequence-related amplified polymorphism,简称SRAP)对栉孔扇贝(Chlamys farreri)(♀)×虾夷扇贝(Patinopecten yessoensis)(♂)子一代及其双亲的遗传变异进行分析.从不同的引物组合中筛选出9对条带清晰、多态性丰富的组合,9对引物共产生了121条扩增带,其中多态性条带107条,平均每对引物组合产生11.89条多态标记.Shannon信息指数I分别为0.299 9、0.218 9、0.334 3,Nei's基因多样性指数h分别是0.196 4、0.141 1、0.218 9,栉孔扇贝与杂交后代的遗传距离是0.107 4,虾夷扇贝与杂交后代的遗传距离是0.228 7,聚类分析也显示了这一特点.从变异贡献率来看,3个群体的总变异中,有37.31%的变异来源于群体间,62.69%的变异来源于个体间.     

The spectroscopic period of the Cepheid SU Cassiopeiae

The spectroscopic period of the short periodic Cepheid SU Cas was determined from the radial velocity measurements by ABT, GIEREN and HÄUPL. The calculated period is 1.949312 days. Radial velocity differences between measurements by GIEREN and HÄUPL are explained as velocity zero point of the used spectrographs. The zero point of the Tautenburg Coudé spectrograph was determined by measuring the radial velocity standard star ϵ Leo. The difference to the standard value was -0.7 km/s. No significant differences are found between the spectroscopic period and light curve of SU Cas in the last 35 years.     

Photometric Follow-up Transit (Primary Eclipse) Observations of WASP-43 b and TrES-3b and A Study on Their Transit Timing Variations

Two photometric follow-up transit (primary eclipse) observations on WASP-43 b and four observations on TrES-3 b are performed using the Xuyi Near-Earth Object Survey Telescope. After differential photometry and light curve analysis, the physical parameters of the two systems are obtained and are in good match with the literature. Combining with transit data from a lot of literature, the residuals (O ? C) of transit observations of both systems are fitted with the linear and quadratic functions. With the linear fitting, the periods and transit timing variations (TTVs) of the planets are obtained, and no obvious periodic TTV signal is found in both systems after an analysis. The maximum mass of a perturbing planet located at the 1:2 mean motion resonance (MMR) for WASP-43 b and TrES-3 b is estimated to be 1.826 and 1.504 Earth mass, respectively. By quadratic fitting, it is confirmed that WASP-43 b may have a long-term TTV which means an orbital decay. The decay rate is shown to be P? = (?0.005248 ± 0.001714) s·yr^?1, and compared with the previous results. Based on this, the lower limit of the stellar tidal quality parameter of WASP-43 is calculated to be ${Q^{\prime }}_{*}\ge 1.5\times {10}^5$, and the remaining lifetimes of the planets are presented for the different ${Q^{\prime }}_{*}$ values of the two systems, correspondingly.     

Research and Test of Real-time Search Algorithm of Fast Radio Bursts Based on GPU Acceleration

In order to satisfy the research need of Nanshan 25 m radio telescope of Xinjiang Astronomical Observatory (XAO) and study the key technology of the planned QiTai radio Telescope (QTT), on the basis of the original CPU (Central Processing Unit)-based real-time search algorithm of FRBs (Fast Radio Bursts), we have studied the GPU (Graphics Processing Unit)-based real-time search algorithm of FRBs, and built the corresponding real-time search system of FRBs. We have made the comparison and analysis on the GPU system and CPU system, the test result shows that under a given searching accuracy, the speed of the GPU-accelerated algorithm is improved by 35–45 times compared with that of the CPU algorithm.     

Low-energy Lunar Trajectories with Lunar Flybystwo

The low-energy lunar trajectories with lunar flybys are investigated based on the Sun-Earth-Moon bicircular problem (BCP). The characteristics of the distribution of trajectories in the phase space are summarized. Using the invariant manifolds in the BCP system, the low-energy lunar trajectories with lunar flybys are sought. Then, take time as an augmented dimension in the phase space of a nonautonomous system, we present the state space map and reveal the distribution of these lunar trajectories in the phase space. Consequently, we find that the low-energy lunar trajectories exist as families, and that the every moment in the Sun-Earth-Moon synodic period can be the departure date. Finally, we analyse the velocity increment, transfer duration, and system energy for the different trajectory families, and obtain the velocity-impulse optimal family and the transfer-duration optimal family, respectively.     

柱撑蛭石吸附去除废水中重金属离子的实验研究

分别利用有机柱化剂十二烷基磺酸钠(SDS)和无机柱化剂聚羟基铝(HA)对蛭石进行柱撑制得十二烷基磺酸钠柱撑蛭石(SDS-V erm icu lite)和聚羟基铝柱撑蛭石(HA-V erm icu lite),并通过XRD、红外光谱、ZETA电位等表征手段对柱撑蛭石进行表征,同时针对柱撑蛭石对Cu2 ,Cd2 ,C r3 3种重金属离子的吸附进行研究,结果表明:吸附去除率受反应时间、重金属离子的初始浓度、pH值等因素的影响,经柱撑后的蛭石对重金属离子吸附的吸附性能比蛭石原矿要强。柱撑蛭石吸附3种重金属离子的动力学吸附过程可用E lov icb方程和双常数方程进行较好的拟合。     

The behaviour of dissolved organic material,iron and manganese in estuarine mixing

Fractionation by ultra-filtration of the dissolved organic material (DOM) in the River Beaulieu, with typical concentrations of dissolved organic carbon (DOC) of 7–8 mg C/l, showed it to be mainly in the nominal molecular weight range of 10³–10⁵, with 16–23% of the total DOC in the fraction > 10⁵. The molecular weight distribution of DOM in the more alkaline River Test (average DOC, 2 mg C/l) was similar. In the River Beaulieu water, containing 136–314 βg Fe/l in ‘dissolved’ forms, 90% or more of this Fe was in the nominal molecular weight fraction > 10⁵. Experiments showed that DOM of nominal molecular weight <10⁵ could stabilize Fe(III) in ‘dissolved’ forms. The concentrations of ‘dissolved’ Fe in the river water probably reflect the presence of colloidal Fe stabilized by organic material and this process may influence the apparent molecular weight of the DOM. Dissolved. Mn (100–136 βg/l) in the River Beaulieu was mainly in true solution, probably as Mn(II), with some 30% in forms of molecular weight greater than ca 10⁴.During mi xing in the Beaulieu Estuary, DOC and dissolved Mn behave essentially conservatively. This contrasts with the removal of a large fraction of the dissolved Fe (Holliday and LISS, 1976, Est. Coastal Mar. Sci. 4, 349–353). Concentrations of lattice-held Fe and Mn in suspended particulate material were essentially uniform in the estuary, at 3.2 and 0.012%, respectively, whereas the non-lattice held fractions decreased markedly with increase in salinity. For Mn the decrease was linear and could be most simply accounted for by the physical mixing of riverborne and marine participates, although the possibility that some desorption occurs is not excluded. The non-linear decrease in the concentration of non-lattice held Fe in particulates reflected the more complex situation in which physical mixing is accompanied by removal of material from the ‘dissolved’ fraction.